Filtralite®: The Next-Gen Filtration Media Reshaping Water and Air Treatment Industries
Introduction
In an era where water scarcity and environmental pollution pose significant challenges, advanced filtration technologies are critical for sustainable industrial operations. Filtralite®, a market-leading porous ceramic and high-performance filter media developed by Saint-Gobain, stands at the forefront of innovation in water and air purification. With applications spanning drinking water treatment (Filtralite® Pure), wastewater purification (Filtralite® Clean), and odor control (Filtralite® Air), this expanded clay aggregate offers superior efficiency, durability, and cost-effectiveness compared to conventional filtration media.
Saint-Gobain, a global industrial leader with a $50 billion turnover in 2024, has leveraged its century-long expertise in clay-based solutions to develop Filtralite®. Manufactured in Norway, Finland, and Portugal, this media is engineered to enhance filtration rates, reduce maintenance costs, and improve water quality—making it an indispensable asset for desalination plants, wastewater treatment facilities, and air purification systems.
From Challenges to Opportunities
Filtration is a crucial aspect of water treatment, directly influencing the quality and efficiency of the final product. Historically, filtration systems have relied on conventional materials such as sand, anthracite, and pumice. These traditional media have provided filtration rates ranging from 4 to 12 meters per hour but are often plagued by issues such as frequent clogging, increased maintenance requirements, and suboptimal water quality. The Silt Density Index (SDI) for these systems typically ranges from 3.5 to 4, which can complicate downstream processes like reverse osmosis that necessitate finer pre-treatment.
In contrast, Filtralite® emerges as a superior alternative, boasting a porous and lightweight structure that allows for filtration rates of up to 20 meters per hour.
The key benefits of Filtralite® include:
- Reduced Clogging: This media addresses the clogging issues common with traditional materials, leading to less downtime and lower operational interruptions.
- Water Savings: Filtralite® requires less frequent backwashing, resulting in significant water savings.
- Enhanced Water Quality: With an SDI consistently below 3, Filtralite® improves compatibility with sensitive downstream processes.
Traditional filtration systems, whether mono or dual media, face inherent limitations, including reduced efficiency in treating poor water quality, mixing of media layers, and increased head loss at higher filtration rates. These systems primarily rely on surface retention, which restricts filtration depth and effectiveness, leading to higher operational and maintenance costs. Filtralite®’s increased porosity accelerates water movement, enhancing filtration rates and retaining more suspended solids. This depth filtration capability prevents clogging at the surface, allowing for more effective treatment. Moreover, Filtralite® can be seamlessly integrated into existing filtration systems, requiring minimal modifications. This adaptability makes it an ideal solution for both new installations and system upgrades.
Advancing Water Treatment Techniques with Filtralite®
Filtralite® is characterized by its tiny, dark-brown to black clay granules, sourced from the cold climates of Northern Europe. The extraction process involves drilling a 3–5 meter hole underground, followed by the removal of impurities using renewable energy sources like biomass. The clay is then subjected to a 58-meter-long rotary kiln, heated to 1200 degrees Celsius, which transforms the clay into a porous media by converting organic materials into volatile gases. This process increases the media’s volume while decreasing its density.
Filtralite® is versatile in its applications:
- Drinking Water Treatment: It can be employed as a single layer with sand or in dual layers without sand, known as mono-multi systems. This differentiates Filtralite® Pure from anthracite, which cannot function effectively as a standalone alternative.
- Desalination: In the pre-treatment stage, Filtralite® can be utilized in single or dual-layer configurations, optimizing the treatment process based on specific requirements.
- Wastewater Treatment: Filtralite® Clean excels in tertiary treatment, leveraging its high number of macropores to reduce ammonia and lower Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) values.
The unique properties of Filtralite® make it an invaluable asset in modern water treatment processes.
Filtralite®: Effective Air Purification Solutions
Odor treatment relies on a straightforward yet effective approach: directing contaminated air through a filtration medium, either upstream or downstream, often accompanied by water sprinkling. Filtralite® Air Filter Material excels in this process due to its unique porous structure, which promotes biofilm growth while ensuring optimal airflow.
Key Advantages of Filtralite® Air
- Enhanced Odor Adsorption
- The material’s high porosity maximizes contact area, allowing greater air volumes to be filtered efficiently.
- Effectively adsorbs H₂S and other odorous compounds, reducing unpleasant smells even before biofilm develops.
- Durability & Structural Efficiency
- Made from natural clay, Filtralite® Air is stable, long-lasting, and free from hazardous additives.
- Its lightweight design exerts five times less structural pressure than conventional materials, lowering construction and removal costs.
- Optimal Filtration Performance
- High surface area and permeability ensure low pressure loss, extended service life, and efficient filtration.
- Creates an ideal habitat for biofilm, boosting biological filtration effectiveness.
- Improved Water Retention & Biological Activity
- The porous structure retains moisture, enhancing trickling efficiency and sustaining continuous microbial activity for consistent odor control.
Case Studies Demonstrating Filtralite®’s Efficacy
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Evaluating Filtralite® Performance: Insights from Suez Tests
Objective of the Study
A comprehensive study was conducted to assess the performance of Filtralite® media in particle retention compared to conventional filter media, as well as to examine the impact of raw water quality and filtration flow rate on filtered water quality and filter productivity.
Testing Site and Methodology
This evaluation took place at the CIRSEE in Le Pecq, where a pilot system comprising five filtration columns was utilized. The pilot was successively fed with two types of water:
- Coagulated Seine River water with turbidity < 20 NTU
- Settled water with turbidity ranging from 0.5 to 5 NTU
Two filtration rates were tested during the study: 8 m/h and 15 m/h.
Performance in Turbidity Removal
The results demonstrated that both conventional filters (sand and sand/anthracite) and Filtralite® media exhibited excellent performance in removing particles, maintaining a filtered water turbidity of 0.2 ± 0.1 NTU. Notably, Filtralite® media achieved the lowest turbidity levels among all tested options.
Filter Productivity (UFRV)
The study also focused on filter productivity (UFRV), revealing that Filtralite® media, especially the Mono-Multi variant, was 1.5 to 2 times more efficient than the best conventional media. Importantly, increasing the filtration rate did not negatively impact the performance of Filtralite®.
Raw Water Quality and Monitoring
Online monitoring revealed the following characteristics of the influent water:
- Average turbidity (raw water):6 NTU (range: 5–20 NTU)
- Average turbidity (settled water):5 NTU (range: 0.5–5 NTU)
- Iron concentration: < 0.05 mg/L
- Natural organic matter: UV254 absorbance = 2.6 m⁻¹ for raw water and 0.6 m⁻¹ for settled water.
Overall, both conventional and Filtralite® filters effectively maintained turbidity at 0.2 ± 0.1 NTU for inlet turbidity levels ranging from 0.5 to 20 NTU. The findings complied with French regulations and SUEZ internal objectives, ensuring that filtered water turbidity remained below 0.5 NTU 100% of the time and below 0.2 NTU 95% of the time, highlighting the effectiveness of Filtralite® as a superior filtration media.
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Industrial air purification in EnergoUtil Plant in Ełk, Poland
Background: Initial Challenges with Traditional Biofilter Media
In 2017, the EnergoUtil plant in Ełk, Poland, faced recurring issues in its air treatment system, which relied on a biofilter media composed of composted materials and bark chips. These materials frequently caked and collapsed over time, reducing permeability, increasing flow resistance, and necessitating frequent and costly media replacement.
Implementation of Filtralite® Air
Seeking a more reliable and sustainable solution, plant engineers conducted a thorough review of available technologies and literature. Their goal was to find a medium that could stabilize operations, reduce maintenance, and maintain high performance over time. The plant introduced 400 m³ of Filtralite® Air 10–20 into its biofilter system—about half the total volume of the filter bed. A layer of birch bark was placed on the surface, and the system was adapted to sprinkle process water over the media three times daily for 20 minutes. This maintained consistent humidity throughout the bed, a critical factor for the biological removal of sulfur compounds.
Results and Operational Improvements
Thanks to the high water retention capacity and structural stability of Filtralite® Air, the plant no longer faced issues of drying or media collapse. According to the plant engineer, “After using the expanded clay fill, we managed to overcome the operational problems we experienced with the previous media. However, the most important thing is that we get stable parameters of biofilters and satisfactory efficiency.”
The modernization not only improved performance but also aligned with the plant’s pro-environmental strategy, significantly reducing odour emissions. Based on the successful outcomes, the plant now plans to construct an additional biofilter, which will also be filled with Filtralite® Air. This case confirms that Filtralite® Air offers a cost-effective, reliable, and environmentally sound solution for industrial air treatment applications—not just in sewage and biogas plants, but across various industries where odour control and system durability are essential.
Mohammed Kastawy Area Sales Manager – MENA Region Mobile: +971565503535 Email : mohammed.kastawy@saint-gobain.com LinkedIn: www.linkedin.com
